过敏性紫癜患儿血清IgA1及其低糖基化水平与肾功能的关系

目的 探讨过敏性紫癜患儿血清IgA1及其低糖基化水平与肾功能的关系.方法 选择过敏性紫癜患儿59例,其中肾损害患儿32例为肾损害组,无肾损害患儿27例为无肾损害组,选择12例健康体检儿童作为对照组.酶联免疫吸附试验（ELISA）法检测血清IgA1与IgA1低糖基化水平即蚕豆凝集素（VVL）和IgA1结合力];肾损害组按IgA1及VVL和IgA1结合力的中位数倍数（MOM）分为：＜0.5 MOM组、0.5～1.5 MOM组和＞1.5MOM组,检测患儿血肌酐（SCr）、尿素氮（BUN）和血尿酸（SUA）水平.结果 对照组IgA1水平及VVL和IgA1结合力分别为（1.07±0.68） g/L、（1.26±0.92） AU/mg,无肾损害组分别为（1.75±0.53） g/L、（2.02±0.76） AU/mg,肾损害组分别为（2.26±0.77） g/L、（3.78±0.64） AU/mg,对照组低于无肾损害组,无肾损害组低于肾损害组,差异均有统计学意义（P＜0.05）.按IgA1水平的MOM分为：＜0.5MOM组（6例）、0.5～1.5 MOM组（17例）和＞1.5MOM组（9例）,三组IgA1水平比较差异有统计学意义（P＜0.01）,但三组SCr、BUN、SUA比较差异无统计学意义（P＞0.05）.按VVL和IgA1结合力的MOM分为：＜0.5MOM组（8例）、0.5～1.5MOM组（13例）和＞1.5MOM组（11例）,三组VVL和IgA1结合力、SCr、BUN比较差异有统计学意义（P＜0.01）,但三组SUA比较差异无统计学意义（P＞0.05）.直线相关分析显示：过敏性紫癜患儿IgA1水平与SCr、BUN、SUA水平无相关性（r=2.88、1.44、1.66,P＞0.05）;VVL和IgA1结合力与SCr、BUN水平呈正相关（r=1.12、1.99,P＜0.05）,但与SUA水平无相关性（r=2.88,P＞ 0.05）.结论 血清IgA1水平不能反映过敏性紫癜肾损害的程度,IgA1低糖基化水平与患儿的肾功能呈正相关,低糖基化水平越高,肾损害程度越重.

Relationship between levels of serum IgA1 and underglycosylated IgA1 and renal function in children with allergic purpura

Objective To discuss the relationship between levels of serum IgA 1 and underglycosylated IgAl and renal function in children with allergic purpura.Methods Fifty-nine children with allergic purpura including 32 cases of renal damage group and 27 cases of non-renal damage group and 12 healthy children as control group were chosen.Enzyme-linked immunosorbent assay （ELISA） was used to detect the levels of serum IgA1 and underglycosylated IgA1the binding capacity of vilsa villosa lectin（VVL） to serum IgA1],children in renal damage group were separated into 3 groups：＜ 0.5 MOM,0.5-1.5 MOM and ＞ 1.5 MOM according to the multiples of the median（MOM） of the level of serum IgA 1 and underglycosylated IgA 1.Serum creatinine （SCr）,blood urea nitrogen （BUN） and serum uric acid （SUA） were tested by completely automatic biochemistry analyzer.Results The levels of serum IgA1 and underglycosylated IgA1 in control group （1.07 ±0.68） g/L,（1.26 ±0.92） AU/mg] were significantly lower than that in renal damage group （2.26 ± 0.77） g/L,（3.78 ± 0.64） AU/mg] and non-renal damage group （1.75 ± 0.53） g/L,（2.02 ± 0.76） AU/mg],and there were differences among these groups （P ＜ 0.05）.According to MOM of the level of serum IgA1：＜0.5 MOM group（6 cases）,0.5-1.5 MOM group（17 cases） and ＞ 1.5 MOM group（9 cases）,there was significant difference in the level of serum IgA1 among three groups （P ＜0.01）,but there was no significant difference of SCr,BUN and SUA among three groups （P ＞ 0.05）.According to MOM of the level of serum underglycoeylated IgA1：＜0.5 MOM group （8 cases）,0.5-1.5MOM group （13 cases） and ＞ 1.5 MOM group （11 cases）,there was significant difference in the level of serum underglycosylated IgA1,SCr,BUN among three groups （P ＜ 0.01）,but there was no significant difference of SUA among three groups （P ＞ 0.05）.Correlation analysis showed that the level of serum IgA1 was no correlation with SCr,BUN,SUA （r =2.88,1.44,1.66,P ＞ 0.05）;the level of serum underglycosylated IgA1 was positive correlation with SCr,BUN（r =1.12,1.99,P＜ 0.05）,but no correlation with SUA（r =2.88,P＞ 0.05）.Conclusions The level of serum IgA1 can＇t reflect the degree of impairment of kidney damage,underglycosylated IgA1 level is significantly positively correlated with the renal function.There are more severe degree of renal function damage in the higher underglycosylated IgA1 level in children with allergic purpura.